In 1992 outlaw fishing boats began illegally harvesting lobsters from the territorial waters
of the country of Belukia. Soon after, the annual tonnage of lobster legally harvested in
Belukian waters began declining; in 1996, despite there being no reduction in the level of
legal lobster fishing activity, the local catch was 9,000 tons below pre-1992 levels. It is
therefore highly likely that the outlaw fishing boats harvested about 9,000 tons of lobster
illegally that year.
Which of the following is an assumption on which the argument depends?
A. The illegal lobster harvesting was not so extensive that the population of
catchable lobsters in Belukia's territorial waters had sharply declined by 1996.
B. The average annual lobster catch, in tons, of an outlaw fishing boat has increased
steadily since 1992.
C. Outlaw fishing boats do not, as a group, harvest more lobsters than do licensed
lobster-fishing boats.
D. The annual legal lobster harvest in Belukia in 1996 was not significantly less than
9,000 tons.
E. A significant proportion of Belukia's operators of licensed lobster-fishing boats
went out of business between 1992 and 1996.

The argument says all the 9,000 tons were caught by illegal harvesting.

However, illegal harvesting started in 1992 and both illegal and legal harvesting co-exist from 1992 to 1996.
So obviously the number of tons harvested is steadily increasing.

What if, the steady increase, reduced the mature lobsters which are ready to offspring in the next year.....
So constantly the source is depleted. This provides an alternative explanation to the decrease instead of assuming the number of lobsters harvested is the same throughout the period 1992-96.

The argument says all the 9,000 tons were caught by illegal harvesting.

However, illegal harvesting started in 1992 and both illegal and legal harvesting co-exist from 1992 to 1996.
So obviously the number of tons harvested is steadily increasing.

What if, the steady increase, reduced the mature lobsters which are ready to offspring in the next year.....
So constantly the source is depleted. This provides an alternative explanation to the decrease instead of assuming the number of lobsters harvested is the same throughout the period 1992-96.

The argument says all the 9,000 tons were caught by illegal harvesting.

However, illegal harvesting started in 1992 and both illegal and legal harvesting co-exist from 1992 to 1996.
So obviously the number of tons harvested is steadily increasing.

What if, the steady increase, reduced the mature lobsters which are ready to offspring in the next year.....
So constantly the source is depleted. This provides an alternative explanation to the decrease instead of assuming the number of lobsters harvested is the same throughout the period 1992-96.

Can you be little more elaborate....

Ok let me try.
Say in 1992 there were 100,000 tons of lobsters. Illegal harvesting:10,000 tons Legal:20,000 tons so we are left with 70,000 tons.

Assuming the harvesting rate remains the same, we started 1992 with 100,000, 1993 with 70,000 : we will have only 40,000 for 1994, 10,000 for 1995 and for 1996 we will not have any lobsters available.

The argument assumes that every year this 100,000 tons remains the same in the starting of every year so the lost 9,000 tons were caught by illegal harvesting team.

Option A says that the population remained the same, confirming the assumption.
Hope it is clear now, if not let me know.
Thanks

The argument says all the 9,000 tons were caught by illegal harvesting.

However, illegal harvesting started in 1992 and both illegal and legal harvesting co-exist from 1992 to 1996.
So obviously the number of tons harvested is steadily increasing.

What if, the steady increase, reduced the mature lobsters which are ready to offspring in the next year.....
So constantly the source is depleted. This provides an alternative explanation to the decrease instead of assuming the number of lobsters harvested is the same throughout the period 1992-96.

Can you be little more elaborate....

Ok let me try.
Say in 1992 there were 100,000 tons of lobsters. Illegal harvesting:10,000 tons Legal:20,000 tons so we are left with 70,000 tons.

Assuming the harvesting rate remains the same, we started 1992 with 100,000, 1993 with 70,000 : we will have only 40,000 for 1994, 10,000 for 1995 and for 1996 we will not have any lobsters available.

The argument assumes that every year this 100,000 tons remains the same in the starting of every year so the lost 9,000 tons were caught by illegal harvesting team.

Option A says that the population remained the same, confirming the assumption.
Hope it is clear now, if not let me know.
Thanks

Hey buddy.....makes little sense now.....however dont you think the arg is contradicting here when it says that annual tonnage of lobster legally harvested is declining but in 96 no reduction in level of legal lobster fishing activity....can you please explain this in more details?

The argument goes like so:
- illegal fishermen started operating in 1992 (premise)
- in 1996, the tonnage for legal fishermen was 9000 tons below pre-1992 levels, despite the fact that legal fishing activity did not go down (premise)
- the only explanation is that poachers were fishing the 9000 tons (conclusion)

Assumptions are logical connections between the premises and the conclusion. It's useful to remember that, if you negate an assumption, then the argument falls apart. The best answer choice here is A, because negating A means that you've destroyed the argument: if indeed the poaching was really big, then the lobster population perished, so the lower catch in 1996 can be explained by the depletion of this resource and NOT by illegal fishing.

B may be true, but it is not an assumption. Think of the case when initial poaching was 1-2 tons and now it is 10 tons. This does not add up to the 9000 tons in the argument.

C doesn't really matter, because we're not comparing them. We're only interested in the impact over the legal fishermen and not how they stack up against poachers.

D doesn't matter either, because this info would only help us evaluate the current catch with the loss.

E - is irrelevant as well, because we are told that no increase in activity occurred. If some went out of business, then others must have taken their place for the activity to stay the same.

The argument goes like so:
- illegal fishermen started operating in 1992 (premise)
- in 1996, the tonnage for legal fishermen was 9000 tons below pre-1992 levels, despite the fact that legal fishing activity did not go down (premise)
- the only explanation is that poachers were fishing the 9000 tons (conclusion)

Assumptions are logical connections between the premises and the conclusion. It's useful to remember that, if you negate an assumption, then the argument falls apart. The best answer choice here is A, because negating A means that you've destroyed the argument: if indeed the poaching was really big, then the lobster population perished, so the lower catch in 1996 can be explained by the depletion of this resource and NOT by illegal fishing.

B may be true, but it is not an assumption. Think of the case when initial poaching was 1-2 tons and now it is 10 tons. This does not add up to the 9000 tons in the argument.

C doesn't really matter, because we're not comparing them. We're only interested in the impact over the legal fishermen and not how they stack up against poachers.

D doesn't matter either, because this info would only help us evaluate the current catch with the loss.

E - is irrelevant as well, because we are told that no increase in activity occurred. If some wenTt out of business, then others must have taken their place for the activity to stay the same.

Thankyou for the explanation Dana.

Can you please elaborate more on option A here....I am still not very clear.....

One more thing you are assuming illegal catching and poaching as same......

Think about it this way: if the illegal catching was extensive, then they might have affected the population of lobsters severely, i.e. there were a lot fewer of them to mate and produce a new generation of lobsters. This is what the author means by catchable lobsters: the full, adult population. If the full adult population had declined, then it's not necessarily that the poachers are catching the extra 9000 tons, it's just that there's fewer lobster left for all types of fishermen.

Think about it this way: if the illegal catching was extensive, then they might have affected the population of lobsters severely, i.e. there were a lot fewer of them to mate and produce a new generation of lobsters. This is what the author means by catchable lobsters: the full, adult population. If the full adult population had declined, then it's not necessarily that the poachers are catching the extra 9000 tons, it's just that there's fewer lobster left for all types of fishermen.

let me c if i got this one now

if option A is negated that means poaching was huge that population of legal or catchable lobster declined.....but the arg says that the legal catch remain the same i mean there is no reduction in legal catch...Does it make sense

also i m not able to relate option A to the conclusion of the argument

conclsuion says it is highly likely that poaching cause 9000 tons of lobster harvesting in 96

but the arg says that the legal catch remain the same i mean there is no reduction in legal catch

This is wrong. The argument says that the legal fishing activity is the same. By fishing activity, they probably understand sailing your boat and putting out nets or whatever. So the fishermen's efforts did not change, but the catch went down. It could have gone down for two reasons:
- poachers got to the 9000 tons
- there are fewer lobsters to catch altogether ---> this possibility is eliminated if we select option A

but the arg says that the legal catch remain the same i mean there is no reduction in legal catch

This is wrong. The argument says that the legal fishing activity is the same. By fishing activity, they probably understand sailing your boat and putting out nets or whatever. So the fishermen's efforts did not change, but the catch went down. It could have gone down for two reasons:
- poachers got to the 9000 tons
- there are fewer lobsters to catch altogether ---> this possibility is eliminated if we select option A

I am sorry Dana....but I am really confused now.......can you please help me showing a connection between option A and the argument in a more elaborate manner.......

Why should you be confused? So you have the argument:
- illegal fishermen started operating in 1992
- legal fishermen were still putting in the same amount of effort in their attempt to catch lobsters, but their overall catch diminished by 9000 tons in 1996 as compared to 1992
- so we need to conclude that the 9000 tons went to the illegal fishermen

But what if there was something else that triggered the decline in the legal fishermen's catch? Option A provides a hint: the catch might have been smaller because the total population of lobsters had declined because of overfishing. If the illegal fishermen had gone too far with fishing in one year, this might have affected the lobster population for years to come, because there were fewer of them mate and produce new lobsters.

Negate B and see if the argument falls apart: The average annual lobster catch, in tons, of an outlaw fishing boat has decreased steadily since 1992. Does this mean that the illegal fishermen could not have been responsible for the 9000 ton decrease? No.

D does not matter, since the amount of decrease/increase in catch or its previous levels are issues not discussed in the argument. The argument is simply trying to establish the source of the decrease.